Dipnet fishermen motor into position on the Kenai River Tuesday afternoon. The river has been taken off the state's list of polluted waterways.

Division of Water spokesman Tim Hoffman said that, after four years on the polluted list, the river's hydrocarbon levels have fallen to acceptable numbers. The department believes the ban on two-stroke boat engines on the river led to the improvement.

Department Environmental Programs Specialist Timothy Stevens said that, at one time, testing on the Kenai found hydrocarbon levels to be twice the accepted levels. He said the department established five potential causes for high petroleum levels: leaks, fuel sales along the river, hardware and storm water run-off.

"We had one small hit of run-off, but we determined the main source to be motor boats," he said.

In response, regulators banned two-stroke motors on the river during the month of July.

With motor restrictions in place, last year the river dropped to half the department's standard during July, which is considered the peak boating time.

Kenai Watershed Forum Executive Director Robert Ruffner said that his group will continue testing the river as part of its Baseline Monitoring Program.

Three other water bodies fell off the polluted list, as well: Jewel Lake and Lake Hood in Anchorage, and Ward Cove near Ketchikan.

State regulators added nine new water bodies to the polluted list. These include five creeks near Coffman Cove in Prince William Sound; Cottonwood Creek, near Wasilla; Red Devil Creek; the Kuskokwim River; and Salt Chuck Bay on Prince of Wales Island.